Patent US4637774A successfully refreshed from Google Patents.
US4435528A
Expired / Lapsed
US
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Concentrated emulsions of water-soluble polymers
Assignee: Dow Chemical Co
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Filing: 1981-12-21
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Granted: 1984-03-06
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Expires: 2001-12-21
Abstract
Abstract Stable concentrated water-in-oil emulsions of water-soluble polymers such as polyacrylamide are provided by concentrating a water-in-oil preconcentrate emulsion of the water-soluble polymer containing an inverting surfactant in an amount sufficient to reduce the bulk viscosity of the preconcentrate emulsion.
Inventors
- 👤 William G. Domina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:24
CPC Classifications
C; C08; C08L; C08L33/00; C08L33/02; C08J; C08J3/00; C08J3/02; C08J3/09; B; B01; B01F; B01F23/00; B01F23/40; B01F23/41; B01F23/414; B01F23/4142; C08J2300/00; C08J2300/14
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
A method for preparing a concentrated stable water-in-oil emulsion containing at least 40 weight percent of a water-soluble polymer which method comprises concentrating a stable preconcentrate water-in-oil emulsion containing a water-soluble polymer in an aqueous phase which is dispersed in a continuous oil phase, said preconcentrate emulsion containing (1) a smaller weight percent of water-soluble polymer than the weight percent thereof in the concentrated emulsion, (2) an emulsifying amount of a water-in-oil emulsifier and (3) an amount of an inverting surfactant sufficient to reduce the bulk viscosity of the preconcentrate emulsion, thereby forming the stable concentrated emulsion.
Claim 2
Independent Claim
97 words
A method for preparing a concentrated stable water-in-oil emulsion containing at least 40 weight percent of a water-soluble polymer which method comprises concentrating a stable preconcentrate water-in-oil emulsion containing a water-soluble polymer in an aqueous phase which is dispersed in a continuous oil phase, said preconcentrate emulsion containing (1) a smaller weight percent of water-soluble polymer than the weight percent thereof in the concentrated emulsion, (2) an emulsifying amount of a water-in-oil emulsifier and (3) an amount of an inverting surfactant sufficient to reduce the bulk viscosity of the preconcentrate emulsion, thereby forming the stable concentrated emulsion.
Claim 3
Dependent Claim
129 words
The method of claim 1 which method comprises the steps of (1) forming a stable water-in-oil emulsion containing at least one water-soluble monomer in an aqueous phase which is dispersed in a continuous oil phase, said emulsion of monomer containing an emulsifying amount of a water-in-oil emulsifier; (2) subjecting said emulsion of monomer to conditions sufficient to polymerize the monomer thereby forming a stable water-in-oil preconcentrate emulsion of a water-soluble polymer; and (3) concentrating said preconcentrate emulsion by removing at least a portion of the water from the preconcentrate emulsion provided that prior to or during step (3) an inverting surfactant is added in an amount sufficient to reduce the bulk viscosity of the preconcentrate emulsion, but less than that which destabilizes the preconcentrate emulsion or the concentrated emulsion.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the inverting surfactant is added prior to step (2).
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein the inverting surfactant is added to the aqueous phase prior to or during the formation of the emulsion of monomer.
Claim 6
Dependent Claim
16 words
The method of claim 3 wherein the inverting surfactant is added to the emulsion of monomer.
Claim 7
Dependent Claim
49 words
A method of claim 3 wherein the inverting surfactant is added to the aqueous phase prior to or during the formation of the emulsion of monomer, and additional inverting surfactant is added during step (3) but before the emulsion is concentrated to a polymer solids of 40 weight percent.
Claim 8
Dependent Claim
23 words
The method of claim 1, 2, 3 or 4 wherein the water-soluble monomer is acrylamide or a mixture of acrylamide and acrylic acid.
Claim 9
Dependent Claim
26 words
The method of claim 7 wherein the amount of inverting surfactant is from about 10 to about 75 weight percent of the weight of water-in-oil emulsifier.
Claim 10
Dependent Claim
15 words
The method of claim 1 wherein the inverting surfactant is added to the preconcentrate emulsion.
Claim 11
Dependent Claim
28 words
The method of claim 1 wherein the inverting surfactant is added during step (3) but before the emulsion is concentrated to a polymer solids of 40 weight percent.
Claim 12
Dependent Claim
27 words
The method of claim 1 wherein the concentration of polymer in the concentrated emulsion is from about 50 to about 77 weight percent of the concentrated emulsion.
Claim 13
Dependent Claim
24 words
A method of claim 1 wherein said concentrated emulsion comprises a weight ratio of polymer to water of from about 0.05:1 to about 0.25:1.
Claim 14
Independent Claim
99 words
A method for preparing a concentrated stable water-in-oil emulsion containing at least 40 weight percent of a water-soluble polymer which method comprises concentrating a stable preconcentrate water-in-oil emulsion containing a water-soluble polymer in an aqueous phase which is dispersed in a continuous oil phase, said preconcentrate emulsion containing (1) a smaller weight percent of water-soluble polymer than the weight percent thereof in the concentrated emulsion, (2) an emulsifying amount of at least two water-in-oil emulsifiers and (3) an amount of an inverting surfactant sufficient to reduce the bulk viscosity of the preconcentrate emulsion, thereby forming the stable concentrated emulsion.
Claim 15
Independent Claim
99 words
A method for preparing a concentrated stable water-in-oil emulsion containing at least 40 weight percent of a water-soluble polymer which method comprises concentrating a stable preconcentrate water-in-oil emulsion containing a water-soluble polymer in an aqueous phase which is dispersed in a continuous oil phase, said preconcentrate emulsion containing (1) a smaller weight percent of water-soluble polymer than the weight percent thereof in the concentrated emulsion, (2) an emulsifying amount of at least two water-in-oil emulsifiers and (3) an amount of an inverting surfactant sufficient to reduce the bulk viscosity of the preconcentrate emulsion, thereby forming the stable concentrated emulsion.
Claim 16
Dependent Claim
24 words
A method of claim 13 wherein said concentrated emulsion comprises a weight ratio of polymer to water of from about 0.05:1 to about 0.25:1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-06 | 1987-09-05 | 1988-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-06 | 1991-09-05 | 1992-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-06 | 1995-09-05 | 1996-03-06 | $7700.00 | Window Closed / Lapsed |